Bit of British culture for you.
While waiting for a train in a WH Smith's newsagent I found a "humour" book in a bargain bin. Titled something like "The Arthur Daley Book of Scams"
Arthur Daley was a British TV dodgy businessman character, with connections to the motor trade.
Flicked through it. The scams I looked at were plausible and some of them I'd seen in action in real life. Wish I'd bought the book.
In Arthurs bio, he was credited with inventing the nylon-shirt-in-the-gearbox trick. If I have another car with a failing gearbox (I once had a Marina gearbox which was mostly filings but continued to shift smoothly) I'll probably try it.